Aircraft typically include a plurality of flight control surfaces that, when controllably positioned, guide the movement of the aircraft from one destination to another. The number and type of flight control surfaces included in an aircraft may vary, but typically include both primary flight control surfaces and secondary flight control surfaces. The primary flight control surfaces are those that are used to control aircraft movement in the pitch, yaw, and roll axes, and the secondary flight control surfaces are those that are used to influence the lift or drag (or both) of the aircraft. Although some aircraft may include additional control surfaces, the primary flight control surfaces typically include a pair of elevators, a rudder, and a pair of ailerons, and the secondary flight control surfaces typically include a plurality of flaps, slats, and spoilers.
The positions of the aircraft flight control surfaces are typically controlled using a flight control surface actuation control system. The flight control surface actuation control system, in response to position commands that originate from either the flight crew or an aircraft autopilot, moves the aircraft flight control surfaces to the commanded positions. In most instances, this movement is effected via actuators that are coupled to the flight control surfaces. Typically, the position commands that originate from the flight crew are supplied via one or more user interfaces or inceptors. For example, many aircraft include duplicate inceptors, such as yokes and pedals, one set each for the pilot and for the co-pilot. Either of the pilot or co-pilot inceptors can be used to generate desired flight control surface actuator commands.
Most modern aircraft are equipped with fly-by-wire flight control surface actuation systems. A typical fly-by-wire system includes, among other devices, electronic sensors, actuator control units, and flight control modules (FCMs). The electronic sensors are coupled to, and sense the positions of, the inceptors, and transmit inceptor position signals to the actuator control units. The FCMs receive aircraft state data supplied from various sensors that monitor the state of the aircraft in flight (e.g., inertial sensors and air data sensors). The FCMs, based at least in part on the aircraft state data, transmit augmentation data to the actuator control units. The actuator control units, which are sometimes referred to as actuator control electronics (ACEs), generate actuator position commands in response to the inceptor position signals and the augmentation data.
The electronic systems and/or sub-systems that are used in aircraft may be subject to various regulatory standards of verification rigor. These standards can prevent or inhibit integration of these electronic systems with other functionalities. These standards can also lead to increased overall implementation costs for such systems, including fly-by-wire systems. There is a desire in the aircraft industry for reduced cost electronic systems, such as fly-by-wire systems. One way of reducing these costs would be to integrate at least portions of the fly-by-wire system with other functionalities. However, presently known fly-by-wire system configurations cannot be integrated with other functionalities and still meet verification rigor standards.
Hence, there is a need for a reduced cost fly-by-wire system that meets verification rigor standards and/or may be at least partially integrated with other functionalities. The present invention addresses at least this need.